The similarities of sleep distributions associated with chronic alcoholism and aging has lead to the speculation that chronic alcoholism leads to "premature aging." The purpose of this research is to evaluate the interaction of age and alcohol on the physiological sleep profile, EEG frequencies and periodicities, and circadian fluctuations of other physiological variables. Sleep studies of dry alcoholics and 24-hour studies of the effect of alcohol on circadian rhythms in alcoholics and age-matched controls are proposed. The data from these studies, combined with our existing data base from previous studies in alcoholics and normals, will allow an extensive evaluation of both alcohol and aging on the phase relationships of EEG activity and other variables. A major emphasis is placed on period analysis of the EEG and time series analyses of physiological data. The implications of this approach to the understanding of a variety of problems, including abuse of alcohol, are outlined.